PRESENTATION ON OVER- SPEED INDICATOR &

ACCIDENT AVOID SYSTEMS

Submitted to: Submitted by:

HARSH HARITT VISHAL SINGLA

HEAD OF DEPTT. 1211461DEPARTMENT OF MECHANICAL ENGINEERING

OVER - SPEED INDICATOR & ACCIDENT AVOIDANCE SYSTEM

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INCREASING POPULATIONINCREASING VEHICLE DENSITYINCREASING SPEEDDIFFICULT TO ADJUST SPEEDLOSS OF PATIENCE

DEFINING OVER-SPEED INDICATOR

Is A Device That Tells The Driver If He / She Is Exceeding The Particular Speed Limit. The System Has A Computer Which Stores The Speed Limits Of Different Areas. The GPS In The System Feeds The Exact Location Of The Car To Determine The Permissible Speed For The Area.

ACCIDENT AVOIDANCE SYSTEMS IS A COCKTAIL OF SEVERAL TECHNOLOGICAL MARVELS TO AVOID ACCIENDNT AS POSSIBLE IT CAN SYSTEMS ARE AS FOLLOWS:1. EMERGENCY BRAKE ASSIST (EBA)

2. DYNAMIC STABILITY AND TRACTION CONTROL (DSTC)

3. ELECTRONIC BRAKE DISTRIBUTION (EBD)

4. ANTI-LOCK BRAKING SYSTEM (ABS)

5. BLIND SPOT INFORMATION SYSTEM (BSIS)

6. NIGHT - VISION

EMERGENCY BRAKE ASSIST (EBA) In an emergency, people do not depress the brake pedal hard enough. EBA senses an emergency braking situation and helps the driver to reduce speed in the shortest distance possible. It interprets braking behaviour by assessing the rate that the brake pedal is activated.improves vehicle and occupant safety, and can reduce stopping distances by up to 70 ft (21 m) at 125 mph (201 km/h)

Some systems additionally take into account the rapidity of which the accelerator pedal is releasedMercedes-Benz & Volvo are successfully brands to use this technologyThe system applies additional brake pressure to allow the driver to take full advantage of the antilock braking system (ABS) which prevents wheel lock up.

HYDRAULIC BRAKE SYSTEM ASSIST

The brake pressure sender in the hydraulic unit, the speed sensors and the brake light switch supply signals to the brake assist system so that it can identify an emergencyPressure is raised in the brake slave cylinders by the actuation of certain valves in the hydraulic unit and the return flow pump for TCS/ESPThese conditions must be fulfilled:1. The signal from brake light switch indicating that

the brakes have been applied.

2. The signals from the speed sensors indicating how fast the vehicle is travelling.

3. The signal from the brake pressure sender indicating how fast and with what force the driver has applied the brakes.

MECHANICAL BRAKE ASSIST SYSTEM

In this case, the valve piston moves and the balls are moved inward in the ball cage. Consequently the locking sleeve can move to its stop. The switch component is locked.  Because the mechanical events are difficult to present in a detailed diagram, the individual steps will be explained in strongly simplified drawings.If the brake is applied too slowly, the brake assist function is not triggered. That means that the driver feels the full counter-pressure from the brake system through the brake pedal as coun- ter-force which he must overcome in order to brake more heavilyIf the brake pedal is pressed very fast, the brake assist function is triggered. The major portion of the counter-force is diverted through the locking of the assembly groups to the housing. The driver has to overcome only a very small force to brake more heavily.

DYNAMIC STABILITY AND TRACTION CONTROL

DSTC makes driving on twisty and slippery road conditions saferBy using sensors to detect whether any of the wheels is losing traction DSTC has the ability to cut power in a flash, helping the car to regain its grip Car shows a tendency to skid, the system automatically slows the particular wheels to help maintain control

THE CAR WITHOUT DSTC SKIDS BUT CAR WITH DSTC REMAINS AS SAME

Braking is automatically applied to wheels individually, such as the outer front wheel to counter over steer or the inner rear wheel to counter under steerSome ESC systems also reduce engine power until control is regainedAccording to Insurance Institute for Highway Safety and the U.S. National Highway Traffic Safety Administration, one-third of fatal accidents could be prevented by the useof the technology The United States Insurance Institute for Highway Safety (IIHS) issued its own study in June 2006 showing that up to 10,000 fatal US crashes could be avoided annually if all vehicles were equipped with ESC. The IIHS study concluded that ESC reduces the likelihood of all fatal crashes by 43%, fatal single-vehicle crashes by 56%, and fatal single-vehicle rollovers by 77–80%

COMPONENTS AND DESIGNESC incorporates yaw rate control Anti-lock brakes enable ESC to brake individual wheels ESC systems also incorporate a traction control systemThe ESC system uses several sensors :1. Steering wheel angle sensor: determines the

driver's intended rotation; i.e. where the driver wants to steer

2. Yaw rate sensor: measures the rotation rate of the car; i.e. how much the car is actually turning

3. Lateral acceleration sensor: often an accelerometer

4. Wheel speed sensor: measures the wheel speed.

ELECTRONIC BRAKE DISTRIBUTION (EBD) Braking forces of the car are distributed between the front and the rear brakes in

order to optimize braking efficiency.

A special function of antilock braking systems (ABS), EBFD makes the amount of brake force applied to a wheel proportional to that wheel’s load at the timeWhen your EBFD system senses that one or more of your wheels is at risk of locking, it will reduce the brake force applied to the affected wheel(s), and, if necessary, apply more brake force to wheels that are not at risk of lockingOne of your wheels is on ice, making it more likely that it will lock and cause your car to spin outAnother motorist does not notice you when making a lane change, and you are forced to brake hard

EBD/EBFD OPERATIONSMADE UP OF THREE SUBCOMPONENTSMONITORED AND GUIDED BY AN ELECTRONIC CONTROL UNIT (ECU)1. speed sensors for each wheel(how fast the wheel

is rotating)2. brake-force modulators(that increases or

decreases brake-force applied to a wheel)3. an acceleration/deceleration sensor(detects the

vehicle’s forward and sideways acceleration/deceleration)

4. a yaw sensor(sensor that monitors a vehicle’s movement along its vertical axis)

The electronic control unit interprets the information from the speed and yaw sensors

sends commands to the brake-force modulators

the ECU in EBFD systems is attached to the hydraulic brake-force modulator

LIMITATIONS WITH EBFD1. Speeding, driving while fatigued, driving with

distractions, tailgating other drivers, and driving in bad weather can all negatively impact the benefits from EBFD because these behaviours impair your ability to drive safely

2. Consume alcohol before driving, for example, will slow your reaction time and make it more difficult to react in emergency situations.

ANTI-LOCK BRAKING SYSTEM (ABS)With ABS you can brake as hard as you can and steer yourself to safety without the fear of wheels locking up and skidding.

with ABS wheels prevent from locking

ALL components are shown in fig.

If the braking force exceeds the force of friction from the road the vehicle will begin to slideWhen a sharp deceleration is detected the ABS will reduce the hydraulic pressure supplied to the braking system until the wheel begins to accelerate againWhen the acceleration is detected the pressure is again increased until an unusual amount of deceleration is detectedProcess is repeated until the user removes their foot from the brake pedal or the vehicle comes to a complete stop.

COMPONENTS OF ABS

1).SPEED SENSORS 2). VALVES 3).PUMP 4).CONTROLLER

1).Speed Sensor

The speed sensor is used to determine the acceleration or deceleration of the wheel.

2). Valves

Serve Three Distinct Functions:

i ). to open and allow the hydraulic fluid from the brake pedal or the pump to reach the braking system

ii). to maintain the current pressure provided to the braking system.

iii). to reduce the amount of hydraulic pressure at the braking system.

3). Pump : is used to restore the pressure to the hydraulic brakes after the valves have released it

4).Controller : The entire system is observed and manipulated by the ABS controller

Controllr

Valves

Pump

Sensor

Plant

BLIND SPOT INFORMATION SYSTEM (BSIS):

Using cameras set just below the outer rear view mirrors the BSDS tell you if there is any vehicle in your blind spot.

that helps detect vehicles in blind spots during normal driving and traffic approaching from the sides when reversing out of parking spots.

HOW IT WORKSThe feature uses two multiple-beam radar modules, the same used with cross-traffic alert, which are packaged in the rear quarter panels – one per side.The radar identifies when a vehicle enters the defined blind spot zone and illuminates an indicator light on the corresponding sideview mirror, providing a warning that a vehicle is approaching.It can pick up a vehicle moving at least 5 mph within a 45-foot range – or five parking spaces – from either the left or right side of the vehicle.When cross traffic is approaching, three warnings are given: an indicator lights up in the corresponding outside mirror, an audible alert is sounded and a message center warning is displayed

The radar also works when backing out of angled parking spaces because its view is wider than just strictly sensing traffic coming at a 90-degree angle

Cross-traffic alert – Warns drivers of impending traffic while backing outRearview and side mirror – Maximum viewing range from conventional rearview and side mirrorsReverse sensing system – Alerts drivers to objects in the vehicle’s path when slowly backing up

NIGHT VISIONDriving during the night becomes safe than ever with the night vision where one can see clearly on the control display even in pitch black. Thanks to infra red technology.

PEDESTRIANS ARE SEEING WITH INFRARED TECHNOLOGY

Night vision is the ability to see in low light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range

Enhanced spectral range allows the viewer to take advantage of non-visible sources of electromagnetic radiation (such as near-infrared or ultraviolet radiation)

Sufficient intensity range is simply the ability to see with very small quantities of light

CATEGORIES OF NIGHT VISION TECHNOLOGY

1. Image Intensification2. Active Illumination3. Thermal Imaging1).Image Intensification:This magnifies the amount of received photons from various natural sources. The image intensifier is a vacuum-tube based device that converts invisible light from an image to visible light so that a dimly light scene can be viewed by a camera or the naked eye.

Light strikes a charged photocathode plate, electrons are emitted through a vacuum tube that strike the micro channel plate that cause the image screen to illuminate with a picture in the same pattern as the light that strikes the photocathode

The image is said to become "intensified" because the output visible light is brighter than the incoming IR light

2). Active illumination :Active illumination couples imaging intensification technology with an active source of illumination in the near infrared (NIR) or shortwave infrared (SWIR) band vision combines infrared illumination of spectral range 700–1,000 nm (just below the visible spectrum of the human eye) with CCD cameras sensitive to this light. The resulting scene, which is apparently dark to a human observer, appears as a monochrome image on a normal display device

3). Thermal vision : Thermal imaging detects the temperature difference between the background and the foreground objects.

Thermal imaging cameras are excellent tools for night vision. They detect thermal radiation and do not need a source of illumination. They produce an image in the darkest of nights and can see through light fog, rain and smoke.

1).Night Vision Control Unit 2).Controller Display 3).Controller

4).Instrument Cluster 5).Button in Light Switch Centre 6). Night-Vision Camera

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